I've had my Signature for ten weeks now. Had to drop it at the service center to get an odd loss-of-navigation fix done, and they gave me a nice rental car - an Altima.
Driving back from Fremont to SF, I realized that I never, EVER want to drive a gasoline car again. Why? Biggest first reason: When you take your foot off the accelerator, it KEEPS GOING! My Tesla regenerates and brakes. In the Altima I found myself running up the back of people ahead of me and having to use a lot of -- horrors! -- braking.
I didn't have my usual acceleration and handling, but bottom line was the thrill of regenerative braking. I hope they only need my car overnight!